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Related papers: Asteroseismology of the visual binary 70 Ophiuchi

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We present the first results of an observational project, which addresses the period changing behaviour of a sample of high-amplitude delta Scuti stars. In this paper we discuss the double-mode nature of V567 Ophiuchi. It was observed on 15…

Astrophysics · Physics 2009-03-09 L. L. Kiss , A. Derekas , Sz. Meszaros , P. Szekely

Rapidly oscillating Ap stars are unique objects in the potential they offer to study the interplay between a number of important physical phenomena, in particular, pulsations, magnetic fields, diffusion, and convection. Nevertheless, the…

Solar and Stellar Astrophysics · Physics 2015-06-17 M. S. Cunha , D. Alentiev , I. M. Brandão , K. Perraut

After a brief introduction into the asteroseismic modelling of stars, we provide a compilation of the current seismic estimates of the core overshooting parameter and of the rotational frequency of single and binary massive stars. These…

Solar and Stellar Astrophysics · Physics 2014-03-05 Conny Aerts

Uncertainties in stellar structure and evolution theory are largest for stars undergoing core convection on the main sequence. A powerful way to calibrate the free parameters used in the theory of stellar interiors is asteroseismology,…

We present interferometric observations of 7 main-sequence and 3 giant stars with spectral types from B2 to F6 using the PAVO beam combiner at the CHARA array. We have directly determined the angular diameters for these objects with an…

If magnetic activity in outer stellar atmospheres is due to an interplay between rotation and subsurface convection, as is generally presumed, then one would not expect to observe indicators of activity in stars with T_eff > 8300 K. Any…

Astrophysics · Physics 2009-11-13 J. E. Neff , T. Simon

More than 40 years of ground-based photometric observations of the delta Sct star 4CVn revealed 18 independent oscillation frequencies, including radial as well as non-radial p-modes of low spherical degree l<=2. From 2008 to 2011, more…

V1022 Cas has been known as a spectroscopic binary for a century. It was found to be eclipsing based on photometry from the Hipparcos satellite, and an astrometric orbit was recently obtained from near-infrared interferometry. We present…

Solar and Stellar Astrophysics · Physics 2020-12-22 John Southworth

We present sub-milliarcseond resolution imaging and modeling of two nearby rapid rotators Alpha Cephei and Alpha Ophiuchi, obtained with the CHARA array - the largest optical/IR interferometer in the world. Incorporating a gravity darkening…

A radial velocity (RV) survey to detect central stars in binary systems was carried out between 2002 and 2004. De Marco et al. (2004) reported that 10 out of 11 monitored stars exhibited strong RV variability, but periods were not detected.…

Astrophysics · Physics 2007-09-12 Orsola De Marco , S. Wortel , Howard E. Bond , Dianne Harmer

The study of eclipsing binaries is our primary source of measured properties of normal stars, achieved through analysis of light and radial velocity curves of eclipsing systems. The study of oscillations and pulsations is increasingly vital…

Solar and Stellar Astrophysics · Physics 2015-09-14 John Southworth

Spectral energy distributions are computed using 2D rotating stellar models and NLTE plane parallel model atmospheres. A rotating, 2D stellar model has been found which matches the observed ultraviolet and visible spectrum of ? Oph. The SED…

Solar and Stellar Astrophysics · Physics 2015-06-04 Robert G. Deupree , Diego Castañeda , Fernando Peña , C. Ian Short

We present a new method for determining the location of active bands of latitude on solar-type stars, which uses stellar-cycle-induced frequency shifts of detectable solar-like oscillations. When near-surface activity is distributed in a…

Over the past decade the study of solar-like oscillations in red-giant stars has developed significantly. Not only the number of red-giant stars for which solar-like oscillations have been observed has increased, but the quality of these…

Solar and Stellar Astrophysics · Physics 2015-05-19 S. Hekker

Environmental effects, such as stellar fly-bys and external irradiation, are thought to affect the evolution of protoplanetary disks in clustered star formation. Previous ALMA images at 225 GHz of the ISO-Oph 2 binary revealed a peculiar…

Small amplitude oscillations are observed in red giant branch (RGB) stars. Data on such oscillations are a source of information about the objects, notably about properties of convection in their envelopes and about the systems these…

Solar and Stellar Astrophysics · Physics 2015-05-20 W. A. Dziembowski , I. Soszynski

Asteroseismology is a powerful tool for probing the internal structures of stars by using their natural pulsation frequencies. It relies on identifying sequences of pulsation modes that can be compared with theoretical models, which has…

The NASA Kepler mission is providing an unprecedented set of asteroseismic data. In particular, short-cadence lightcurves (~60s samplings), allow us to study solar-like stars covering a wide range of masses, spectral types and evolutionary…

The measured properties of stellar oscillations can provide powerful constraints on the internal structure and composition of stars. To begin this process, oscillation frequencies must be extracted from the observational data, typically…

Solar and Stellar Astrophysics · Physics 2009-11-13 Brendon J. Brewer , Dennis Stello